Tranexamic Acid
⚠️ Caution: Use carefully in patients with gross haematuria - clot formation may lead to urinary tract obstruction.
💊 About
- Tranexamic acid is a synthetic antifibrinolytic agent that prevents excessive bleeding by stabilising clot formation.
- It is commonly used in haemorrhage prevention and control across surgical, obstetric, and trauma settings.
- Always check the BNF for indication-specific dosing and contraindications.
🧬 Mode of Action
- Tranexamic acid competitively inhibits plasminogen activation to plasmin, reducing fibrin degradation.
- This stabilises existing clots and slows fibrinolysis, thereby decreasing active bleeding.
- Unlike pro-coagulants, it does not increase clot formation - it simply prevents clots from breaking down prematurely.
🎯 Indications
- 🩸 Heavy menstrual bleeding (menorrhagia).
- 🦷 Dental extractions in haemophiliacs (mouthwash or oral).
- 🏥 Prostatectomy and bladder surgery – limits intraoperative bleeding.
- 👃 Epistaxis – topical or oral therapy to control nosebleeds.
- 👁️ Traumatic hyphaema – stabilises intraocular bleeding.
- 👩⚕️ Obstetric bleeding / postpartum haemorrhage (per NICE NG121).
- 🧠 Trauma (CRASH-2 trial): 1 g IV stat, then 1 g over 8 hours – reduces mortality if given within 3 hours of injury.
- 🫀 Cardiac and orthopaedic surgery: reduces transfusion requirements without clear thromboembolic risk.
- ⚡ Hereditary angioedema: used prophylactically to reduce attack frequency.
💉 Dosing (Typical Adult Regimens)
| Indication | Typical Dose | Route / Duration |
| Menorrhagia | 1 g TDS | PO for 4 days during menses |
| Epistaxis | 1 g TDS | PO for 7 days |
| Perioperative Bleeding | 10 mg/kg | IV before incision, repeat 6–8 hourly |
| Trauma (CRASH-2) | 1 g IV over 10 min → 1 g IV over 8 h | Within 3 h of injury |
| Local Fibrinolysis (e.g. TURP) | 1 g TDS | IV or PO as indicated |
⚕️ Dose Adjustments
- 🧮 Renal impairment: reduce dose or extend dosing interval due to renal excretion.
- 💉 Administer IV slowly over ≥10 minutes to avoid hypotension or dizziness.
🚫 Contraindications
- Active intravascular clotting or history of thromboembolic disease.
- Acquired colour vision defects (used for monitoring toxicity in long-term therapy).
- Gross haematuria (risk of clot retention).
- Pregnancy: no known teratogenicity, but use with caution - tranexamic acid crosses the placenta.
⚠️ Adverse Effects
- 🧠 Seizures (rare, dose-related; associated with high-dose cardiac surgery use).
- 🩸 Pro-thrombotic tendency - uncommon but possible in predisposed individuals.
- 🤢 GI upset: nausea, vomiting, diarrhoea.
- 😵 Dizziness, headache, fatigue.
- 🌡️ Hypersensitivity reactions: rash, urticaria, or anaphylaxis (rare).
💬 Teaching Pearls
- 💡 TXA prevents breakdown of existing clots - it does not initiate coagulation.
- 🕒 In trauma, timing is crucial: administration >3 hours post-injury offers no benefit.
- 🫀 In cardiac surgery, seizure risk rises with doses >100 mg/kg - use minimal effective dose.
- 🩺 When using in haematuria, consider bladder irrigation to prevent clot retention.
📚 References
- BNF: Tranexamic Acid
- CRASH-2 Trial Collaborators. Effects of Tranexamic Acid on Death, Vascular Occlusive Events and Transfusions in Trauma. Lancet 2010;376(9734):23–32.
- NICE NG121: Intrapartum Care and Postpartum Haemorrhage (2023)
- Society of Thoracic Surgeons Blood Conservation Guidelines (2022)
